Not going into reasons for/against training and job options afterwards, BUT,
Wouldn't it be easier to remortgage property? What's the rough repaid equity on mortgage, or is it wholly owned/repaid/paid total in cash?
BBVA has been known to lend specifically larger amounts for flight training.
I'm sure you can borrow more if you have large enough equity on property, but no idea about the UK vs Spanish property thing. Just few other thoughts/considerations, maybe.